Geology Exam 2
relative age: ______ order of geological events
chronological
folds are a cause of ______ stress
compressional
there is ______ stress (push together) at reverse thrust faults
compressional
______ collision can cause metamorphism as rock at surface is pushed down deeper
continental
compression leads to _____
contraction (shortening)
contraction features are prominent at _____ boundaries
convergent
the largest earthquakes occur at ______ plate boundaries, associated with TSUNAMIS
convergent
seismic waves _____ back to surface when density increases with depth
curve
in strike-slip faults, blocks move ____
horizontally
increase of depth leads to ______ in pressure
increase
P-waves move through the ______ of the earth
interior
schist is ______ to high grade
intermediate grade
the number of earthquakes varies ______ with magnitude
inversely
types of fractures:
joints, cracks/breaks
earthquake amplitude scales are _____, meaning each unit is a factor of 10
logarithmic
L-waves (___) are _______ waves
love, surface
heat spurred by nearby _______ moves away as magma _______ which causes metamorphism
magma, cools
__________ __________ indicates the intensity of metamorphism
metamorphic grade
the higher the temp. and pressure, the higher the ______
metamorphic grade
_________ is a transformation of a ______ to another rock, for all 3 rock types
metamorphism, protolith
any type of rock can be _____
metamorphosed
metamorphism can cause change in...
mineralogy and texture
____ accumulate in fault lines
minerals
_________ is the group (assemblage) of minerals that make up a rock
minerology
normal faults lead to chairs of _____
mountains
at the s-wave shadow zone there are _____ s-waves
no
absolute age (____ age): assigns an age using ____
numerical, tools
seismic waves helped discover the earths liquid _____ core by the s-wave _____ zone and the p-wave shadow zone
outer, shadow
after gneiss, ______ melting leads to migmatite
partial
folds are also _____ deformation
plastic
earthquakes show boundaries of _____ ______
plate tectonics
even stress on all sides creates ____
pressure
there are different ______-______ paths of metamorphism
pressure-temperature
P-waves (_____) are fast and the first waves we feel
primary
_______ metamorphism means increasing pressure and temperature
prograde
rock it was before
protolith
tension causes geologic features to ____ ____
pull apart
in reverse (thrust) faults, one block is _____ up
pushed
R-waves (______) are also ______ waves
rayleigh, surface
seismic waves ______ and ______
refract, reflect
at the p-wave shadow zone, P-waves are highly ______
refracted
geologic time describes both ____ and _____ terms
relative, absolute
______ metamorphism means lowering the pressure and temperature
retrograde
contraction features include:
reverse/thrust faults, folding
earthquake magnitude can be measured by ________ scale or________ magnitude
richter, moment
the ______ _______ explains the rock transformations between ______, ______, and _______
rock cycle, igneous, metamorphic, sedimentary
P waves travel through both solid ______ and ______ but are slower in liquid
rock, liquid
s-waves (______) are slower than P-waves and also move through the _______
secondary, interior
relative age principle of original horizontality
sediments are deposited in horizontal layers
________ _______ are vibrations in the rock generated by rupture along a fault
seismic waves
earthquakes are the ______ of the ground caused by _____ waves
shaking, seismic
progressive metamorphism of shale is...
shale to slate to schist to gneiss
shear leads to _____
shear
a change in texture can be through....
size and shape of crystals in rock
shear makes geologic features _____ past each other
slide
metamorphic reactions are very _______ but are sped up when you have _____ in rock
slow, fluids
there are lots of ______ earthquakes and few _____ earthquakes
small, big
metamorphism occurs in the _____ state
solid
once an S wave hits liquid, it ____
stops
deformation results when geologic stress leads to ____
strain
______ is needed for foliation
stress
ruptures are caused by accumulation of _____
stress
_____-_____ faults occur at shear transform boundaries
strike-slip
example of contraction
subduction zones, continental collisions
a _____ is a fold shaped like a trough
syncline
compression pushes geologic features ____
together
anticlines and synclines can occur ______ and are often part of the _____ structure
together, same
_______ boundaries are responsible for significant earthquake risk (San Andreas Fault in CA)
transform
shear features are prominent at _____ boundaries
transform
these rock ______ are driven by ______ ______
transformations, plate tectonics
different ______ of P and S waves help locate earthquake _____
velocities, epicenters
in strike-slip faults, the fault plane is nearly ____
vertical
a joint is
volcanic lava flow
relative age principle of superposition
younger deposition of sediments has younger on top
a displacement is a form of _____ deformation
brittle
fractures are a form of _____ deformation
brittle
the epicenter is the point on the surface directly _____ the focus
above
the fault plane at reverse thrust faults is at an _____
angle
an ______ is a fold shaped like an arch
anticline
earthquakes are initiated by a _____ or ______ in a fault
break, shift
metamorphism occurs _____ in the earth's crust
deep
geologic stress leads to ____
deformation
different types of plate interactions at boundaries lead to _____ styles of deformation
different
faults are cracks/breaks with _____
displacement
smaller earthquakes occur at ______ boundaries
divergent
in normal faults, one block ______ down
drops
______ deformation results in squishing rather than shatterng
ductile
tension results in ______
elongation (stretching)
elongation features are prominent at _____ boundaries
extensional
in normal faults, there is ______ stress (pull apart)
extensional
folds: formerly _____ layers bent into folds
flat
circulation of _______ also causes metamorphism
fluids
fault ruptures initiate at the _______ (also known as the hypocenter_
focus
underground point on fault plain where movement starts
focus
folds are a type of ____ deformation
folds
alignment of crystals
foliation
there are _____ types of seismic waves
four
The 4 Fs of deformation are:
fractures, folds, faults, foliation
_______ is the highest grade of metamorphic rock
gneiss
metamorphism can be caused by...
heat, pressure, and fluids
